The field of this invention is medical infusion pumps. More specifically, this invention is an infusion pump which has programmable delivery profiles, and which can be programmed to be used with a variety of intravenous ("IV") infusion sets using various types of tubing with various sizes and physical characteristics that impact delivery profiles.
A variety of infusion pumps and controllers exist in the prior art. Commonly, an IV administration set is used with a disposable reservoir bag and a flexible IV tube. The tubing has within it a drip chamber to eliminate bubbles in the fluid in the tubing. The distal end of the tubing has a intravenous needle for insertion into the patient. Traditionally the reservoir bag is raised above the patient and drained by gravity into the patient.
Infusion pumps and controllers were developed to attach to the outside of the tubing to control the rate of flow from the reservoir bag into the patient. The controllers would constrict the tubing or unconstrict it over time to control the flow by gravity to the patient. Infusion pumps use the power of the pump to move the fluid to the patient and do not use the elevation of the bag above the patient to determine the pressure in the tubing.
Some infusion pumps use a chamber of a known volume. The rate of flow of the pump is controlled by controlling the number of times in a period that the chamber is filled and pumped out.
Many infusion pumps are peristaltic pumps. Peristaltic pumps in the prior art are of two types, finger peristaltic pumps and rotary peristaltic pumps. Finger peristaltic pumps have a row of fingers or depressors along a section of the tubing. The fingers are depressed in a series or waves creating a moving contraction along the tubing which pumps the fluid through the tubing. Rotary peristaltic pumps have a number of arms on a rotor. Each arm has a roller at the end of the arm. As the rotor rotates in a circular chamber, the rollers on the end of the arms roll along and constrict the tubing lining the outer surface of the chamber. This creates a series of rolling contractions through the tubing that pumps the fluid through the tubing.
A primary limitation of the gravity infusion bag is that the pressure (and therefore the flow rate) of the fluid is determined by the height at which the bag is hung above the patient. Furthermore, the prior art peristaltic pumps are calibrated to deliver the requested flow rate for a specific size and type of tubing. Therefore, a different prior art peristaltic pump is required for each tubing size and type.